Capturing wind into batteries on the prairie
LUVERNE -- Roughly the size of two semi trailers and weighing nearly 80 tons, groundbreaking wind-to-battery technology was unveiled in the middle of farm fields northwest of Beaver Creek Monday morning.
The battery, the first of its kind to be tested in the United States, will help partners Xcel Energy and Luverne-based Minwind Energy capture and store power produced by the 11.5-megawatt Minwind Energy wind farm.
"You don't have to drive very far outside of Luverne to see the progress that we've made," said Dave Sparby, president and CEO of Northern States Power Co., a subsidiary of Xcel Energy. "Whether it's the wind turbines on the Buffalo Ride or the high voltage transmission lines ... we've seen that renewable energy can power the Midwest."
Minnesota is leading the charge, with Xcel Energy producing 1,100 megawatts of wind power to serve more than a quarter million homes around the state.
"We are the No. 1 wind provider in the country," said Frank Novachek, director of corporate planning for Xcel Energy. "We have led the industry in carbon reductions, investments in solar energy and in new technology (such as the wind-to-battery project)."
Novachek said the 1 megawatt sodium sulfur battery at the Minwind site can store enough energy to power 500 homes for up to seven hours. Storing the power will give Xcel Energy the ability to reduce the cycling of power plants, better regulate volt frequency on the transmission and distribution system and allow the company to "hedge its bets" on natural gas generation during peak periods.
"Just imagine having wind power without the wind blowing," said Sparby, referring to those early July days when demand for cool, air-conditioned homes and businesses far outweighs the amount of energy being produced by the wind turbines that dot the southwest Minnesota landscape.
"Battery technology allows us to take that clean energy, store it when it's available and use it when it's most needed," Sparby said.
Storage can increase the financial value and enhance the environmental value of energy, he added.
"We have renewable mandates in Minnesota, but we hope to go beyond those mandates," Novachek said. "We think storage can help us do that."
Novachek said the work being done near Beaver Creek is a small test by utility standards. The battery at the site has an estimated lifespan of 15 years, but the first three of those years will be filled with testing, according to Mark Willers, CEO of Minwind Energy.
"There's a great wind resource in southwest Minnesota and we have a very interesting partner in Minwind," said Novachek.
Minwind Energy produces 11.5 megawatts of power per day -- almost enough to supply the entire city of Luverne, which uses approximately 13 to 14 megawatts per day, said Willers. The energy produced by the turbines near Beaver Creek is added to the grid that stretches from Sioux Falls, S.D., to Minneapolis.
"The power goes wherever it's needed," said Willers.
Minwind Energy is comprised of 360 local investors who raised the capital to construct the wind farm. They each have a stake in the ownership of the turbines. Willers said the group is "very interested" in what's going on in regard to energy production.
Minwind recently completed a two-year test project with Xcel Energy on a biodiesel peaking plant, in which a 99 percent blend of biofuels was used to power the wind turbines when Mother Nature didn't provide enough wind for them to operate.
"We're locally owned and we understand what energy is," said Willers. "As Minnesotans, we want to have an understanding of where our energy dollars are going and coming from. Being an agricultural community, we're always on the forefront of environmental issues."
Xcel Energy is also involved in other test projects, including a wind-to-hydrogen project outside Boulder, Colo., a compressed air energy storage project and a pumped air hydro project also in Colorado.